Abstract Every production process, in general, requires a thorough inspection in order to meet user specific standard. For example, in the avionic sector, visual inspection and quality control procedures are extremely important, since the critical parts such as oil ducts of the gearbox and engine components are often contaminated. Currently, the inspection procedures are carried out by workers and exploiting some primary level of instruments such as endoscope or fiberscope. As human operation causes errors, the deficiency in the inspection cannot be nullified completely. Hence, the goal of this study is to design a novel automated robotic probe for reducing the critical level of these visual inspections. The proposed inspection system is suited for checking ducts and cavities, with some channels thinner than 6 mm in diameter. The robotic probe has been developed and tested in a real industrial scenario; a real aircraft gearbox has been inspected with the proposed probe and it successfully identified unwanted residuals such as sand, machining swarf, metallic dust and obstructions. This paper describes how the inspection system is developed using a flexible probe and its capability to perform standard and reproducible inspection of complex ducts, bends and different pathways.